关联查询指定表的字段
Flight表关联了多张表，如果不指定字段，默认会返回所有，显得找起来很麻烦，尤其是表中很多字段的情况！
php
$result = Flight::query()
->where(['fltNr' => $id])->with([
'flightPlayers',
'flightPlayers.relation',
'flightPlayers.greenfee',
'flightPlayers.sales',
'flightPlayers.sales.item',
'flightPlayers.sales.salesTransaction',
])->first();输出结果
json
{
"fltNr": 9451976,
"fltComNr": 9,
"fltRefType": null,
"fltRefNr": null,
"fltDate": 738084,
"fltTime1Booked": 580,
"fltTimeFixedYN": null,
"fltTime1": 580,
"fltBreakTime": null,
"fltTime2": 720,
"fltCrlNr1": 44,
"fltCrlNr2": 0,
"fltAloneYN": null,
"fltHole": null,
"fltOrigin": null,
"fltSize": 3,
"fltCheckedIn": 0,
"fltTimestamp": "2020-08-20 15:51:37",
"fltCarNr": null,
"fltNotes": null,
"fltDownPaymentPerc": null,
"fltPaid": null,
"fltAgtNr": null,
"fltHotNr": null,
"fltOptionDate": null,
"fltCcard1": null,
"fltCcard2": null,
"fltCcardExpMonth": null,
"fltCcardExpYear": null,
"fltCcardCode": null,
"fltCcard3": null,
"fltCcard4": null,
"fltResNr": null,
"fltCost": null,
"fltStatus": null,
"fltHosNrLocked": 94,
"fltCheckResult": null,
"fltHosNr": 94,
"fltEmpNr": 24,
"flight_players": [{
"flpNr": 29803563,
"flpFltNr": 9451976,
"flpMatch": null,
"flpSide": 1,
"flpRelNr": 309,
"flpRelNrWildcard": null,
"flpName": "Slof",
"flpGrpNr1": null,
"flpGrpNr2": null,
"flpGrpNr3": null,
"flpExtra": null,
"flpPhone": "0172617000",
"flpEmail": "595@mms.nl",
"flpHandicap": 25.1,
"flpGrfNr": 7,
"flpGfcNr": null,
"flpItmNr": 212,
"flpPrice": 25,
"flpBilNr": null,
"flpGrfNrDiscount": null,
"flpGfcNrDiscount": null,
"flpItmNrDiscount": null,
"flpDiscount": null,
"flpSalNrDiscount": null,
"flpVoucher": null,
"flpScorecard": null,
"flpQualifying": null,
"flpCarNr": null,
"flpIntro": null,
"flpTeebox": null,
"flpCheckResult": null,
"flpRelNrMain": null,
"flpEmailMarkNY": 1,
"relation": {
"relNr": 309,
"relRelNrMain": null,
"relComNr": 9,
"relType": null,
"relName": "Slof",
"relGender": 1,
"relFirstName": "D",
"relPrefix": "",
"relRtlNr": 1,
"relAddress1": "Stik van Linschoten 22",
"relAddress2": "Stik van Linschoten 22",
"relCity": "Bergdorp",
"relPostalCode": "2411 PZ",
"relState": null,
"relCouNr": 1,
"relPhone": "0172617000",
"relPhoneMobile": "0172617000",
"relPhoneWork": "0172617000",
"relFax": null,
"relEmail": "595@mms.nl",
"relEmailVerifyCode": null,
"relEmailWork": null,
"relDateBirth": 717929,
"relCreatedDate": null,
"relHandicap": 25.1,
"relGolferId": null,
"relMemberCode": "142",
"relMemberType": "a",
"relExternalId": null,
"relDebtorId": null,
"relMaxCredit": null,
"relValue1": null,
"relValue2": null,
"relValue3": null,
"relGrfNr": null,
"relGrfNrDiscount": null,
"relRelNrCompany": null,
"relDftContactYN": null,
"relRelNrDebtor": null,
"relRelNrMail": null,
"relLngNr": null,
"relEmpNr": null,
"relRbrNr": null,
"relEndBlockDate": null,
"relGrpNr1": 136,
"relGrpNr2": 2580,
"relGrpNr3": 2581,
"relDontCheckYN": null,
"relPliNr": null,
"relSupplierYN": null,
"relImage": "https:\/\/s3-eu-west-1.amazonaws.com\/intogolf.nl\/new-avatar\/IoXwfFyPPg545W5LGDmhfy67ksQNCncor9e7e10C.jpeg",
"relNotes": null,
"relActualYN": 1,
"relHandicapYN": null,
"relCoursePermissionYN": null,
"relBankAccount": null,
"relChargeBankYN": null,
"relRttNr": null,
"relCallName": "Dirk",
"relVatId": null,
"relLastChanged": null,
"relIBAN": null,
"relBIC": null,
"relGolfPermitDate": null,
"relCoursePermDate": null,
"relRulesExam": null,
"relHomeclub": null,
"full_name": "D Slof",
"age": 55
},
"greenfee": {
"grfNr": 1,
"grfComNr": 9,
"grfOrdering": 10,
"grfName": "Standaard Greenfee",
"grfDateFrom": 737790,
"grfDateTo": 738155,
"grfIntroYN": 0,
"grfDiscountYN": 0,
"grfCardYN": 0,
"grfDiscountCardYN": 0,
"grfRounds": 0,
"grfRoundType": 1,
"grfCardPrice": 0,
"grfCardDuration": 12,
"grfCardDurationType": 0,
"grfActualYN": 0,
"grfWildcardYN": 0,
"grfFreePriceYN": 1,
"grfCardDiscount": 0,
"grfMlaNrCard": null,
"grfMaxPerPeriod": 0,
"grfMaxPeriod": 0
},
"sales": [],
"rateList": {
"1": {
"grfNr": 7,
"grfName": "Greenfeee",
"grfCard": 0,
"grfDiscountCard": 0,
"grfDiscount": 0,
"price": 0.02,
"itmNr": 212,
"gfcNr": null
}
},
"discountList": [{
"grfNr": 0,
"grfName": "...",
"grfCard": 0,
"grfDiscountCard": 0,
"grfDiscount": 1,
"price": 0,
"itmNr": 0
}],
"isSelected": false,
"flpFullName": "D Slof (Dirk)"
}]
}下面我们优化，只输出前台用到的字段
php
$result = Flight::query()
->select('fltNr', 'fltDate', 'fltTime1', 'fltTime2', 'fltCrlNr1', 'fltCrlNr2')
->with(['flightPlayers:flpNr,flpFltNr,flpBilNr,flpRelNr,flpGrfNr,flpScorecard',
'flightPlayers.greenfee:grfNr,grfName,grfCardPrice,grfRoundType,grfOrdering,grfDateFrom,grfDateTo',
'flightPlayers.relation:relNr,relName,relImage,relRtlNr,relMemberCode,relCity,relPhone,relGolferId,relAddress1,relDateBirth,relEmail,relHandicap,relFirstName,relCallName,relGender,relGrpNr1,relLastChanged',
'flightPlayers.sales:salNr,salTrnNr,salBilNr,salItmNr,salVat,salBilNr,salAmount,salTrnNr',
'flightPlayers.sales.item:itmNr,itmName,itmPrice,itmIsgNr,itmSellYN',
'flightPlayers.sales.salesTransaction:trnNr,trnTimestamp'
])
->where(['fltNr' => $id])
->first()需要注意，我们需要指定主键名称。 如 Flight 表和 flightPlayers 表是一对多关联，flpNr字段是flightPlayers表的主键，大概格式就是
->with[
'关联表1:关联表主键1,字段1,字段2'
'多级关联表1.多级关联表2:关联表主键2,字段1,字段2'
]